When you consider how much time, effort, and money goes toward creating clean, safe drinking water, every drop should make it to the consumer.
Yet 7.5 to 20 percent of treated water is reported as “unaccounted for water” across the U.S., according to a 2002 report by Beecher Policy Research, Inc.
Much of that loss is due to leakage in distribution pipes.
“There are leaks in every water distribution network around the world,” said Dimitris Chatzigeorgiou, a PhD candidate at the Massachusetts Institute of Technology (MIT). “It is a big concern, and water authorities are spending a lot of money trying to prevent it.”
Chatzigeorgiou and his colleges at MIT’s Mechatronics Research Laboratory (MRL), along with the King Fahd University of Petroleum and Minerals (KFUPM), have created one technology that might just do the trick.
MRL’s in-pipe leak detection robot uses pressure gradients to identify leaks. The detector — which operates autonomously — can sense leaks at any angle around the circumference of the pipe with only two sensors. This method is more accurate than the acoustic leak detection systems most commonly used, said Chatzigeorgiou.
“Fixed acoustic systems are installed in fixed places around the network and have to listen for leaks day and night. They need many sensors throughout the pipe or there will be blind spots and false positives in the network,” said Chatzigeorgiou. “This type of system works alright with metal pipes, but with plastic pipes there are challenges because the sound dissipates quickly.”
Mobile acoustic leak detection systems, which are also commonly used, have limitations as well, said Chatzigeorgiou. These systems require a map of the network, which isn’t always available or up to date. Most mobile systems also work above ground, and small leaks can go unnoticed because the sound is too quiet to travel up to the surface.
MRL’s leak detection system takes a different approach.
“The concept behind the detection system we propose is based on the fact that any leakage in a pipeline alters the pressure and flow field of the working medium,” explained Chatzigeorgiou. “More specifically, there is a fluidic region in the neighborhood of a leak that is characterized by a rapid change in static pressure, dropping from high-pressure inside the pipeline, to low pressure in the surrounding medium resting outside. This pressure gradient is apparent in all pressurized pipes in the vicinity of leaks and or openings.”
This technique works regardless of pipe size or material. It also remains relatively insensitive to fluid medium inside the pipes, which makes the detection method widely applicable. The pipes do not have to be drained to install the detection technology, and no interruption in service is necessary.
MRL’s leak detection technology is still in the research stages, but has been demonstrated in the U.S. and Saudi Arabia. The funding for the project originally came from the Saudi Arabian government, which was interested in the technology because the country was losing precious desalinated water through leaks in its distribution pipes. MRL is in talks with various companies to commercialize the technology, and Chatzigeorgiou feels it will be on the market in the next one to two years.
“This method is more reliable and more robust than what is out there,” he said. “It has been successful so far and we will continue to demonstrate its benefits.”
For more information visit http://ccwce.mit.edu/
Image credit: "Water main break in the 500 block of Hampton Park BLVD on 7/13/2011.," markn3tel © 2011, used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by/2.0/